1. Field of the Invention
The present invention relates to a display operation device for giving an instruction to electronic equipment and, more specifically, to a display device receiving a user instruction using a user interface (UI) component such as a software button as a trigger of some process, as well as to an image processing apparatus having such a display operation device.
2. Description of the Background Art
As one type of image processing apparatuses as electronic equipment, image forming apparatuses (typically, copy machines) are introduced to many places of business (companies and offices). A main function of an image forming apparatus is to form an image on a sheet of recording paper. Therefore, it is often the case that the image forming apparatus has a printer function, a copy function and the like. The image forming apparatuses are often connected to a network, to allow use by a plurality of users. A multifunction peripheral (MFP) has been known as one type of such image forming apparatuses. An MFP has a scanner function, and has a plurality of basic operational modes such as a copy mode, a facsimile mode (hereinafter “facsimile” may also be denoted as FAX or fax), and a network-supported printer mode. It is expected that the scanner function will be used more frequently in the future in such image forming apparatuses. In the copy mode and facsimile mode also, it is possible to read an image using the scanner function and to set functions such as duplex (two-sided) printing, collective printing (such as 2-in-1 by which two pages of an original document are printed on one sheet, or 4-in-1 by which four pages of an original document are printed on one sheet), and enlargement or reduction of size.
When using such an image forming apparatus, by way of example, the user makes the following operations. First, the user has image data read by the image forming apparatus in the scanner mode. Thereafter, the user inputs various instructions through an operation panel, and performs image processing (such as collection). Then, the user gives an instruction to start a final processing of the image (printing to a sheet of paper, transmission by facsimile, and saving as a file). A screen image allowing setting of functions in various operational modes, for example, is displayed on the operation panel. Therefore, it is possible for the user to easily set various functions.
Recently, a touch-panel display comes to be increasingly used as such an operation panel. A touch-panel display includes a liquid crystal panel (display panel) and a touch-panel stacked on the liquid crystal panel. Typically, items (software buttons) allowing selection of an operational mode of the image forming apparatus are displayed on the touch-panel display. Viewing the display, the user presses a position where a desired item is displayed, on the touch-panel display. For the user, it seems as if he/she has pressed a software button. Information related to which position has been pressed is transmitted to a computer controlling the image forming apparatus, and what operation is to be carried out is determined in accordance with the position, by a program running on the computer.
The touch-panel display provides both the display function and the operation function. It is advantageous in that it occupies a smaller area for installation than a display unit and an operation unit provided separately, it allows various and many manners of display, and it provides various and many functions.
By way of example, when an MFP having a touch-panel display as such as an operation panel is in the copy mode, a copy start key (button) is displayed on the display as an initial screen image. If the copy start key is pressed, using this as a trigger, the MFP automatically reads a document placed on an automatic document reader and forms a copy on a sheet of recording paper.
After the start of copying, the user may want to stop copying by some reason. For this purpose, it is a general practice to display a copy stop key together with the copy start key, allowing the user to stop copying by pressing the copy stop key once the copying operation is started. However, this hinders efficient use of the area of touch-panel display. Considering the fact that MFPs come to have various and many functions, many pieces of information must be displayed on the display, and such pieces of information must be displayed in an easily viewable and easily understandable manner. Therefore, the area of touch-panel display should not be wasted.
In order to solve such a problem, Japanese Utility Model Laid-Open Application No. 59-58457 (hereinafter referred to as '457 Reference) discloses a technique of using one switch both as a copy start switch and a copy stop switch. Specifically, '457 Reference discloses a technique in which during a copy operation, the copy start key is used as a copy stop key. In the device disclosed in this reference, either one of two indications “START” and “STOP” lights up on a hardware key. The indication corresponding to the usable function lights up on the key.
Other main functions of the MFP include a document reading function, used in copying and facsimile transmission. Similar problem as described above occurs when the MFP reads documents. Further, it is often the case that, at the time of document reading, after a document is read by the MFP, the user wishes to have an additional document read. It is not efficient to provide a key dedicated for additional document reading. Japanese Patent Laying-Open No. 2005-64944 (hereinafter referred to as '944 Reference) discloses a technique in which the initially displayed read start button is displayed as an additional read start button. Specifically, the characters displayed on the button are changed from “read start” to “additional read start.”
The technique described in '457 Reference and the technique described in '944 Reference are based on similar ideas of allocating different functions to one key or button (hereinafter referred to as “button or the like”) and switching the functions to be used. These are good techniques that allow advantageous use of the display area.
These techniques, however, still have room for improvement. Specifically, in both techniques, it is difficult to understand the function allocated to the button or the like, until the user reads the characters displayed on the button or the like. Particularly, in '457 Reference, one key has opposite functions of “start” and “stop,” while in '944 Reference, one key has similar functions of “read start” and “additional read start”. Therefore, when different functions are allocated to one button, it is difficult to recognize whether the functions are similar to or very much different from each other. Such a problem arises not only on software buttons but also on general UI components (for example, pull-down menu, combo boxes, tabs, table cells or icons, texts or images used in place of software buttons) used as a trigger of a task on a display-operation panel.